Technical Imaging | The Art Institute of Chicago


Robert Lifson has extended been the qualified standing behind that digicam. A senior photographer in our Imaging division, Robert has taken a good a lot of photos in his 30 decades at the Art Institute. One day he graciously permitted us to drop into his studio and enjoy him operate.

The subject matter that day was a popular painting by the Spanish artist Salvador Dalí. When Inventions of the Monsters entered our assortment, the artist wrote to congratulate the Art Institute and to explain that the ominous temper of his work and its monsters could be attributed to Europe’s march to war in the 1930s. It is one particular of our most well-liked Surrealist operates.

We’ll enable Robert acquire it from here.

Robert at operate in the images studio

The Undertaking

Though I normally do superior-excellent photographic captures for publication, my job these days is technical imaging, which is finished for conservation and science investigate. The Artwork Institute is a very little little bit exclusive in that we’ve integrated specialized imaging right here in our common photography studio. Today I’m capturing photographs of Dalí’s portray making use of six unique kinds of gentle: normal, infrared, ultraviolet, axial, transmitted, and raking. Conservators will use these a variety of images to assistance assess the issue of the painting. They are searching for complications like cracks or unstable paint, so they really don’t require or want a fairly photograph. They want to see what is actually going on—on and under the surface.

As far as this Dalí painting goes, there are no real troubles this suite of photos was requested by conservation as element of an ongoing technical review on the artist, carried out in collaboration with the curators of the forthcoming exhibition Salvador Dalí: The Graphic Disappears.

See of Inventions of the Monsters on an easel and shot in usual light

The over impression was shot with usual light, the kind I would use for publication-good quality images, even though I would alter the lights extra and perhaps use unique polarizing filters. Persons normally talk to about the coloration charts (the grids of shade, to the still left of the painting in the shot higher than). Not to get too complex, but these charts are applied both equally to calibrate the camera with a color profile and then for steerage down the road for someone who may well just have the image file and not the work to compare it to. Utilizing the exact color profile that we present together with the color chart, they’ll know exactly if and what color changes are necessary. The compact chart (on the base), now all grey, will gentle up in coloration to reveal that a UV light-weight is currently being shone on the painting. And individuals black and white discs (on the suitable) are called Spectralons, which can properly tell us the worth of the light by its reflectance benefit, which we can evaluate.

The Rig

I use a Hasselblad, a high-close 4-shot digital camera. That usually means that each pixel is divided into 4 sections, and the sensor shifts 4 moments all through exposure to seize the RGB shade channels—red, environmentally friendly, and blue—extremely accurately. Then it places all of that information and facts alongside one another and provides not only incredibly accurate coloration but unbelievable sharpness and depth. To get even more depth and better top quality, I seize the painting in thorough sections and then stitch it collectively.

Ultraviolet Gentle

Mild, as you may perhaps recall from faculty, is the variety of electromagnetic radiation that is obvious to the naked eye. At the significantly close of this slim noticeable spectrum, just under seen light-weight, we have ultraviolet light-weight (UV). Even though we can not see it, UV is even now referred to as light-weight. Nonetheless, simply because certain substances fluoresce (or gentle up) when they take in UV, it’s extremely handy for researching artworks.

Grab the arrows in the middle of the slider and look at ordinary mild (slide left) versus UV light (slide proper) .

See the designs of the varnish on the area when you pull the arrows all the way to the right.

For the most section, UV is a topical light, and by that I mean it activates the surface area. And due to the fact most paintings are coated with varnish of one particular type or a different, UV is a excellent way to look at the varnish and see how it lays on the area. Specific minerals in pigments, these as cadmium or zinc, also fluoresce, so UV imaging can assist conservators identify what kind of paint was used. When previous varnish is taken off from paintings, they will search entirely distinctive under UV light-weight because distinct minerals have a probability to absorb the UV.

Infrared light

Infrared light or IR has a wavelength that’s more time than the visible purple. It’s outside of what we see as a color and not seen to the human eye. Because it is emitted by all resources of noticeable light—such as light-weight bulbs or the sun—most cameras are sensitive to it and have a built-in IR filter. At our request, the Hasselblad we use does not have a developed-in filter, so for regular pictures, we set on our very own filter, but when we want to penetrate and see underneath the paint, we can use IR.

Commonly, we will seize IR in two various ways. 1 lighting the painting with regular mild from the back—called transmitted light—capturing an infrared impression from the front. This will demonstrate us particulars on the again of the canvas. The other way is flashing a normal light on the entrance of the painting. This IR seize is good at revealing what is likely on with the canvas less than the paint.

Grab the arrows in the middle of the slider and examine entrance gentle (slide left) compared to back again light-weight (slide ideal).

Two views captured using infrared light

The information conservators are seeking for with IR has nothing at all to do with colour they’re hunting for grid strains or pencil marks the artist manufactured or even seeking for destruction to the canvas alone. So the very best way to reveal this info beneath the paint is in black-and-white.

Transmitted light

Transmitted light-weight is yet another tactic that uses backlighting. For this, we put the canvas on a distinctive easel that retains the portray in area at the leading and the base. Then we block out every thing close to it and glow light-weight at the again of the canvas and towards the camera. This time, nevertheless, we place the IR filter on the lens. The outcome is a extraordinary picture that provides conservators a feeling of the thickness of the layers and displays spots where by the paint is opaque or perhaps cracked.

Seize the arrows in the center of the slider and review again lighting captured with an IR filter off (slide left) and an IR filter on (slide correct).

Raking and Axial light

Raking and axial light are two versions of shining a ordinary light on the front of a portray. Raking gentle is when a gentle is positioned at a steep angle to the painting and shines throughout the floor. This topographical perspective shows the problem of the paint on the area and the canvas alone, highlighting any 3-dimensional features these types of as ripples or cracks. It’s the exact impact as when sunlight comes by the window and reveals contours on a wall or the flooring.

Axial gentle is when a gentle is directed straight on a get the job done and you can see vibrant reflections from the surface that generate a glare, particularly the place it’s glossy. These are named specular highlights, which is what we try to stay away from in any other sort of pictures. It’s a topographical see like raking, but it shows a topography of contrasts instead than shadows. It is also a way to document floor sheen (the variation involving gloss and matte regions on the paint). Both equally techniques support reveal the contours and patterns of paint and varnish as they were being applied.

Grab the arrows in the center of the slider and review axial gentle (slide left) with raking gentle (slide proper).

Discover the contours of the portray with the raking mild as opposed to the specular highlights captured making use of axial light-weight.

Closing views

Every single impression form reveals some thing distinctive, and of class the insights they give range from artwork to artwork. It can be some thing insignificant, like pencil marks put down by the artist, which may possibly reveal a little something about the artist’s course of action. Or it can expose a important situation, specially if a do the job has suffered problems, which in turn can have a big affect on how the perform is conserved.

It’s been genuinely fascinating looking at these distinctive photos with conservators, as they’re the professionals. When I initial started with technical imaging, the conservators would come down and reveal, “Oh, that inexperienced is since of a varnish” or they would place out an attention-grabbing glow that indicated a certain variety of mineral in the pigments. And jointly we would start to regulate the amount of gentle and how that mild hits or reflects on the operate. I’ve acquired a great deal from them, from their exhilaration in sharing their understanding, and it aids me make a decision how to change lights or solution some thing special.

Positive, there are lots of subtleties, but in essence, it is all about placing up the lights, deciding how a lot light then goes into the exposure, and how it will come back to the digital camera. I have undoubtedly realized to see attributes that are integral to the portray but might be invisible to the eye—though not to the digital camera. I’m usually bowled around by what specialized imaging reveals and how significantly extra it can help me appreciate works of art.

—Robert Lifson, senior photographer, Imaging

Discover extra about the forthcoming exhibition Salvador Dalí: The Picture Disappears.


  • Conservation
  • Individuals
  • The Digital Museum

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